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A093420 Triangle read by rows: for 1 <= k <= n, numerator of a(n, k) = [prod_{i = 0..k-1} n-i]/[sum_{i = 1..k} i]. 3
1, 2, 2, 3, 2, 1, 4, 4, 4, 12, 5, 20, 10, 12, 8, 6, 10, 20, 36, 48, 240, 7, 14, 35, 84, 168, 240, 180, 8, 56, 56, 168, 448, 960, 1440, 1120, 9, 24, 84, 1512, 1008, 2880, 6480, 10080, 8064, 10, 30, 120, 504, 2016, 7200, 21600, 50400, 80640, 725760, 11, 110, 165 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

a(n, n) = 2*(n-1)!/(n+1).

A093421 gives the denominators.

CROSSREFS

Cf. A093412, A093421, A093422.

Sequence in context: A162915 A092565 A021452 * A104897 A185694 A097510

Adjacent sequences:  A093417 A093418 A093419 * A093421 A093422 A093423

KEYWORD

nonn,easy,frac,tabl,less

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 30 2004

EXTENSIONS

Edited and extended by David Wasserman (dwasserm(AT)earthlink.net), Aug 29 2006

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Last modified February 14 08:37 EST 2012. Contains 205614 sequences.